如何在Android中的GridView中的imageView上设置布局参数

我是新来的android和我在官方的android网站上见过这个教程如何创建一个图像的GridView 。 我正在使用kotlin作为选择的语言。 在扩展BaseAdapter的适配器类中,我试图按照教程中的说明设置imageview的layoutparams,但是我得到一个错误,说GridView.LayoutParams是未解决的引用。 以下是该课程的完整代码:

 class ImageAdapter(val context: Context) : BaseAdapter() { // references to our images val items: IntArray = intArrayOf(R.drawable.cat, R.drawable.daft_punk, R.drawable.gun, R.drawable.harvestors, R.drawable.intel, R.drawable.maserati, R.drawable.porsche, R.drawable.serveroom, R.drawable.spiderman, R.drawable.watch_dog) override fun getItem(p0: Int): Any { TODO("not implemented") //To change body of created functions use File | Settings | File Templates. } override fun getItemId(p0: Int): Long { return 0 } override fun getCount(): Int { return items.size } // create a new ImageView for each item referenced by the Adapter override fun getView(p0: Int, p1: View?, p2: ViewGroup?): View { var imageView: ImageView if (p1 == null) { // if it's not recycled, initialize some attributes imageView= ImageView(context) imageView.layoutParams= GridView.LayoutParams(85,85) imageView.scaleType = ImageView.ScaleType.CENTER_CROP imageView.setPadding(8, 8, 8, 8) } else { imageView=p1 as ImageView } imageView.setImageResource(items[p0]) return imageView } } 

该错误是在getView方法在线imageView.layoutParams=GridView.LayoutParams(85,85)LayoutParams是红色的,这意味着错误,当我把它悬停在上面,我得到的消息:

未解决的参考:LayoutParams

我如何成功设置这些LayoutParams ? 因为如果没有它们, GridView中的图像将显示在它们的完整高度,我需要一个小图像,就像Gallery应用程序在手机中显示的一样。

后续问题:

当我用imageView.layoutParams=GridView.LayoutParams(85,85) imageView.layoutParams=AbsListView.LayoutParams(85,85)替换imageView.layoutParams=GridView.LayoutParams(85,85)时,我得到一个javaOutOfMemory错误。 以下是完整的堆栈跟踪:

 08-16 06:58:11.412 4543-4543/gallerie.classmite.com.imageviewer E/dalvikvm-heap: Out of memory on a 18662416-byte allocation. 08-16 06:58:11.431 4543-4543/gallerie.classmite.com.imageviewer E/AndroidRuntime: FATAL EXCEPTION: main Process: gallerie.classmite.com.imageviewer, PID: 4543 java.lang.OutOfMemoryError at android.graphics.BitmapFactory.nativeDecodeAsset(Native Method) at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:609 at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:444) at android.graphics.drawable.Drawable.createFromResourceStream(Drawable.java:840) at android.content.res.Resources.loadDrawable(Resources.java:2166) at android.content.res.Resources.getDrawable(Resources.java:710) at android.widget.ImageView.resolveUri(ImageView.java:638) at android.widget.ImageView.setImageResource(ImageView.java:367) at gallerie.classmite.com.imageviewer.ImageAdapter.getView(ImageAdapter.kt:32) at android.widget.AbsListView.obtainView(AbsListView.java:2372) at android.widget.GridView.makeAndAddView(GridView.java:1345) at android.widget.GridView.makeRow(GridView.java:345) at android.widget.GridView.fillDown(GridView.java:287) at android.widget.GridView.fillFromTop(GridView.java:421) at android.widget.GridView.layoutChildren(GridView.java:1233) at android.widget.AbsListView.onLayout(AbsListView.java:2166) at android.view.View.layout(View.java:15127) at android.view.ViewGroup.layout(ViewGroup.java:4862) at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1888) at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1742) at android.widget.LinearLayout.onLayout(LinearLayout.java:1651) at android.view.View.layout(View.java:15127) at android.view.ViewGroup.layout(ViewGroup.java:4862) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:515) at android.widget.FrameLayout.onLayout(FrameLayout.java:450) at android.view.View.layout(View.java:15127) at android.view.ViewGroup.layout(ViewGroup.java:4862) at com.android.internal.widget.ActionBarOverlayLayout.onLayout(ActionBarOverlayLayout.java:374) at android.view.View.layout(View.java:15127) at android.view.ViewGroup.layout(ViewGroup.java:4862) at android.widget.FrameLayout.layoutChildren(FrameLayout.java:515) at android.widget.FrameLayout.onLayout(FrameLayout.java:450) at android.view.View.layout(View.java:15127) at android.view.ViewGroup.layout(ViewGroup.java:4862) at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2315) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2021) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1189) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6221) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:788) at android.view.Choreographer.doCallbacks(Choreographer.java:591) at android.view.Choreographer.doFrame(Choreographer.java:560) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:774) at android.os.Handler.handleCallback(Handler.java:808) at android.os.Handler.dispatchMessage(Handler.java:103) at android.os.Looper.loop(Looper.java:193) at android.app.ActivityThread.main(ActivityThread.java:5315) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:829) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:645) at dalvik.system.NativeStart.main(Native Method) 

只有当我在手机中运行应用程序时,才会出现错误,但是当我在模拟器中运行应用程序时,它会在上面进行更换后完美地工作。

你可以试试这个:

 imageView.layoutParams = AbsListView.LayoutParams(85, 85) 

在检索childs的LayoutParams时,在GridView使用AbsListView.LayoutParams

由于静态成员可以被Java中的子类继承。 当你调用GridView.LayoutParams ,它实际上是AbsListView.LayoutParams 。 但是,在Kotlin,你不能以同样的方式去做。 在子类之外,只能使用超类的名称引用超类的伴随对象的成员。

后续问题的更新:

OutOfMemory错误表示您正在将大图像加载到ImageView 。 为了防止这种情况发生,您必须在显示图像之前缩小图像,参考本教程 。 您也可以使用一些图像加载框架(如Glide )来显示图像。

建议阅读: 将图像加载到Bitmap对象时出现内存不足的问题

不要像以前那样设置布局参数

正确的方法是imageParams =(GridView.LayoutParams)imageView.getLayoutParams();

在上面的行中“GridView”应该替换为您的imageView的父视图

快乐编码.. 🙂